问：PDP激活接受消息中的PDP地址IE和PCO IE中的地址

爱卫生

规范里有说明的。

在Create PDP Context Response消息中，

“PDP Address is included if the GGSN allocated a PDP address. If the GGSN has been configured by the operator to use External PDN Address Allocation for the requested APN, PDP Address shall be set to 0.0.0.0, indicating that the PDP address shall be negotiated by the MS with the external PDN after completion of the PDP Context Activation procedure. “

另外，这两者的作用分别是：

The purpose of the packet data protocol address information element is to identify an address associated with a PDP.

以及“The purpose of the protocol configuration options information element is to:

- transfer external network protocol options associated with a PDP context activation, and

- transfer additional (protocol) data (e.g. configuration parameters, error codes or messages/events) associated with an external protocol or an application.”也就是说，PDP address也就是一个地址标识，而PCO则可以用于传递一些外部PDN网络的辅助信息，例如DNS服务器地址或DHCP服务器地址等，PDP地址可以等PDP激活流程完了以后，MS再根据收到的DHCP服务器地址，去向这个PDN网络里的DHCP服务器去申请。